Information rates for multiantenna systems with unknown fading

This work first presents a general technique to compute tight upper and lower bounds on the information rate of a multiuser Rayleigh fading channel with no channel state information (CSI) at the transmitters or the receivers. The paper then presents analytical upper and lower bounds on the information rate which converge in the limit of large number of transmitting users where the channel bandwidth is large compared to the user data rates, e.g., when users can employ CDMA. In this limit, the capacity (per Hz) of the individual users is decreasing while the sum capacity (per Hz) is constant. The paper concludes with exact analytical expressions for the information rates of both the block fading and the continuous correlated fading channel models in this regime.